In the previous report, the authors discussed the single and double-hole models and riveted joint as crack arresters and experimentally checked by brittle fracture propagation test. They concluded that the behavior of crack arrester for brittle fracture can be estimated on the basis of fracture mechanics considerations. In this report a kind of fundamental crack arrester model i, e, patch type model is analized by elasticity theory and discussed its effectiveness and effect of its geometrical factors. Though experimental data are lacking the results of calculation would be useful for future consideration and optimum design of crack arrester for brittle fracture. Experimental check and additional discussions will be reported in the next report.